zbMATH — the first resource for mathematics

Examples
Geometry Search for the term Geometry in any field. Queries are case-independent.
Funct* Wildcard queries are specified by * (e.g. functions, functorial, etc.). Otherwise the search is exact.
"Topological group" Phrases (multi-words) should be set in "straight quotation marks".
au: Bourbaki & ti: Algebra Search for author and title. The and-operator & is default and can be omitted.
Chebyshev | Tschebyscheff The or-operator | allows to search for Chebyshev or Tschebyscheff.
"Quasi* map*" py: 1989 The resulting documents have publication year 1989.
so: Eur* J* Mat* Soc* cc: 14 Search for publications in a particular source with a Mathematics Subject Classification code (cc) in 14.
"Partial diff* eq*" ! elliptic The not-operator ! eliminates all results containing the word elliptic.
dt: b & au: Hilbert The document type is set to books; alternatively: j for journal articles, a for book articles.
py: 2000-2015 cc: (94A | 11T) Number ranges are accepted. Terms can be grouped within (parentheses).
la: chinese Find documents in a given language. ISO 639-1 language codes can also be used.

Operators
a & b logic and
a | b logic or
!ab logic not
abc* right wildcard
"ab c" phrase
(ab c) parentheses
Fields
any anywhere an internal document identifier
au author, editor ai internal author identifier
ti title la language
so source ab review, abstract
py publication year rv reviewer
cc MSC code ut uncontrolled term
dt document type (j: journal article; b: book; a: book article)
Stability and bifurcation in a harvested one-predator–two-prey model with delays. (English) Zbl 1097.34051
This paper mainly concerns the stability and bifurcation of a delayed one-predator-two-prey model with harvesting of the predator at a constant rate. It is shown that time delay can cause a stable equilibrium to become unstable. By choosing the delay as a bifurcation parameter, Hopf bifurcation can occur as the delay crosses some critical values. The authors also investigate the direction and stability of the Hopf bifurcation by following the procedure of deriving a normal form given by T. Faria and L. T. Magalhães [J. Differ. Equations 122, No. 2, 181–200 (1995; Zbl 0836.34068)]. Finally, an example is given and numerical simulations are performed to justify the theoretical results.
MSC:
34K18Bifurcation theory of functional differential equations
34K20Stability theory of functional-differential equations
92D40Ecology
92D25Population dynamics (general)